edible marine bivalve having a fluted fan-shaped shell that swim by expelling water from the shell in a series of snapping motions

edible muscle of mollusks having fan-shaped shells; served broiled or poached or in salads or cream sauces

one of a series of rounded projections (or the notches between them) formed by curves along an edge (as the edge of a leaf or piece of cloth or the margin of a shell or a shriveled red blood cell observed in a hypertonic solution etc.)